﻿using System;
using System.Drawing;
using System.Runtime.InteropServices;

namespace MPR
{
    /// <summary>
    /// 播放MP3文件
    /// </summary>
    public class Mp3Player
    {
        //定义API函数使用的字符串变量
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        private string Name = "";

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
        private string durLength = "";

        [MarshalAs(UnmanagedType.LPTStr, SizeConst = 128)]
        private string TemStr = "";

        private int ilong;

        //定义播放状态枚举变量
        public enum State
        {
            mPlaying = 1,
            mPuase = 2,
            mStop = 3
        };

        //结构变量
        public struct structMCI
        {
            public bool bMut;
            public int iDur;
            public int iPos;
            public int iVol;
            public int iBal;
            public string iName;
            public State state;
        };

        public structMCI mc = new structMCI();

        //取得播放文件属性
        public string FileName
        {
            get
            {
                return mc.iName;
            }
            set
            {
                //ASCIIEncoding asc = new ASCIIEncoding();
                try
                {
                    TemStr = "";
                    TemStr = TemStr.PadLeft(127, Convert.ToChar(" "));
                    Name = Name.PadLeft(260, Convert.ToChar(" "));
                    mc.iName = value;
                    ilong = APIClass.GetShortPathName(mc.iName, Name, Name.Length);
                    Name = GetCurrPath(Name);
                    //Name = "open " + Convert.ToChar(34) + Name + Convert.ToChar(34) + " alias media";
                    Name = "open " + Convert.ToChar(34) + Name + Convert.ToChar(34) + " alias media";
                    ilong = APIClass.mciSendString("close all", TemStr, TemStr.Length, 0);
                    ilong = APIClass.mciSendString(Name, TemStr, TemStr.Length, 0);
                    ilong = APIClass.mciSendString("set media time format milliseconds", TemStr, TemStr.Length, 0);
                    mc.state = State.mStop;
                }
                catch
                {
                }
            }
        }

        //播放
        public void play()
        {
            TemStr = "";
            TemStr = TemStr.PadLeft(127, Convert.ToChar(" "));
            APIClass.mciSendString("play media", TemStr, TemStr.Length, 0);
            mc.state = State.mPlaying;
        }

        //停止
        public void StopT()
        {
            TemStr = "";
            TemStr = TemStr.PadLeft(128, Convert.ToChar(" "));
            ilong = APIClass.mciSendString("close media", TemStr, 128, 0);
            ilong = APIClass.mciSendString("close all", TemStr, 128, 0);
            mc.state = State.mStop;
        }

        public void Puase()
        {
            TemStr = "";
            TemStr = TemStr.PadLeft(128, Convert.ToChar(" "));
            ilong = APIClass.mciSendString("pause media", TemStr, TemStr.Length, 0);
            mc.state = State.mPuase;
        }

        private string GetCurrPath(string name)
        {
            if (name.Length < 1) return "";
            name = name.Trim();
            name = name.Substring(0, name.Length - 1);
            return name;
        }

        //总时间
        public int Duration
        {
            get
            {
                durLength = "";
                durLength = durLength.PadLeft(128, Convert.ToChar(" "));
                APIClass.mciSendString("status media length", durLength, durLength.Length, 0);
                durLength = durLength.Trim();
                if (durLength == "") return 0;
                return (int)(Convert.ToDouble(durLength) / 1000f);
            }
        }

        //当前时间
        public int CurrentPosition
        {
            get
            {
                durLength = "";
                durLength = durLength.PadLeft(128, Convert.ToChar(" "));
                APIClass.mciSendString("status media position", durLength, durLength.Length, 0);
                mc.iPos = (int)(Convert.ToDouble(durLength) / 1000f);
                return mc.iPos;
            }
        }
    }

    public class APIClass
    {
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        public static extern int GetShortPathName(
        string lpszLongPath,
        string shortFile,
        int cchBuffer
        );

        [DllImport("winmm.dll", EntryPoint = "mciSendString", CharSet = CharSet.Auto)]
        public static extern int mciSendString(
        string lpstrCommand,
        string lpstrReturnString,
        int uReturnLength,
        int hwndCallback
        );
        [DllImport("User32.dll")]
        public static extern IntPtr GetWindowDC(IntPtr hwnd);

        [DllImport("user32", EntryPoint = "GetDesktopWindow")]
        public static extern IntPtr GetDesktopWindow();
        [DllImport("gdi32.dll")]
        public static extern bool BitBlt(IntPtr hdcDest, int nXDest, int nYDest, int wDest, int hDest, IntPtr hdcSource, int xSrc, int ySrc, CopyPixelOperation rop);
        [DllImport("kernel32.dll")]
        public static extern bool Beep(int freq, int duration);
        [DllImport("winmm.dll")]
        public static extern long waveOutSetVolume(UInt32 deviceID, Int32 Volumea);
        [DllImport("winmm.dll")]
        public static extern long waveOutGetVolume(UInt32 deviceID, out Int32 Volumea);
        //寻找目标进程窗口
        [DllImport("USER32.DLL")]
        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
        [DllImport("USER32.DLL", EntryPoint = "FindWindowEx", SetLastError = true)]
        public static extern IntPtr FindWindowEx(IntPtr hwndParent, uint hwndChildAfter, string lpszClass, string lpszWindow);
        //设置进程窗口到最前
        [DllImport("USER32.DLL")]
        public static extern bool SetForegroundWindow(IntPtr hWnd);
        //模拟键盘事件
        [DllImport("USER32.DLL")]
        public static extern void keybd_event(Byte bVk, Byte bScan, Int32 dwFlags, Int32 dwExtraInfo);
        public delegate bool CallBack(IntPtr hwnd, int lParam);
        [DllImport("USER32.DLL")]
        public static extern int EnumChildWindows(IntPtr hWndParent, CallBack lpfn, int lParam);
        //给CheckBox发送信息
        [DllImport("USER32.DLL", EntryPoint = "SendMessage", SetLastError = true, CharSet = CharSet.Auto)]
        public static extern int SendMessage(IntPtr hwnd, UInt32 wMsg, int wParam, int lParam);
        //给Text发送信息
        [DllImport("USER32.DLL", EntryPoint = "SendMessage")]
        private static extern int SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, string lParam);
        [DllImport("USER32.DLL")]
        public static extern IntPtr GetWindow(IntPtr hWnd, int wCmd);
        [DllImport("USER32.DLL")]
        public static extern bool SwitchDesktop(IntPtr hDesktop);
    }
}
